28 articles since 2024

How things actually work

I write about backend engineering: networks and protocols, databases, system design, authentication, and now and then what is going on inside an AI model. Usually it is me taking something apart and writing down what I found.

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Computer Networks6 Oct 202628 min

Two Backends, One VPS, One Caddy: The Docker DNS Collision That Ate Half My API Traffic

For about six days, my product was broken in the most annoying way a product can be broken: it failed the first time you used it, and then it worked.

Docker
DevOps
Networking

System DesignSept 20266 min

Designing APIs: Part 1 – REST, gRPC and tRPC

Whenever we build a backend application, the first decision we need to make is how the client and server will communicate. This decision determines how data travels over the network, and…

api-design
rest

AI & LLMsJul 20267 min

What Actually Happens When You Send a Message to ChatGPT?

You type a question, hit enter, and a few seconds later you have an answer that reads like a human wrote it. It feels a little like magic. It isn't. It's math, at a scale that's hard to picture…

chatgpt
openai

Security & AuthApr 202611 min

How OIDC and OAuth Actually Works Under the Hood ?

There is a good chance you have used "Login with Google" a hundred times without thinking twice about what is happening behind the scenes. And if you are building something, you have probably…

authentication
OIDC

DatabasesApr 20263 min

Joins in SQL Explained.

What are SQL Joins and Why do we need it ? In relational databases, data is intentionally split across multiple tables to avoid duplication and maintain consistency. This concept is called…

Databases
joins

DatabasesApr 20265 min

All you need to know about SQL Queries

In this article, we will cover how to write SQL commands, along with a few tips and things to keep in mind while writing queries, and how to write optimized queries. SQL commands are categorized…

Databases
sql Queries

DatabasesApr 20266 min

Your Data Is Not Actually Stored in a Database

While you may wonder why I wrote this title, but you will get the point once you read the whole article. So whenever we talk about databases, one thing that comes to our mind is that to store data…

Databases
SQL

System DesignMar 20265 min

System Design : Consistent Hashing

Why do we need Consistent Hashing ? Imagine you are building a bookMyShow system which is used to book tickets. Initially what would be your system? All user requests (search, booking, payments)…

ChaiCode
ChaiCohort

System DesignMar 20263 min

System Design: Understanding Kafka Architecture

Suppose you are watching a cricket match IND vs AUS, World Cup Final 2023 :( . While checking the live score, you expect updates to appear in the correct sequence. For example: After 2 overs → IND…

System Design
ChaiCode

System DesignMar 20266 min

System Design : Message Queue (RabbitMQ)

What is a Queue? A queue is a fundamental concept in software engineering used to manage tasks or messages that need to be processed in a specific order (FIFO). It provides a mechanism for…

ChaiCode
System Design

System DesignMar 20266 min

System Design: Scaling Databases to Millions – Complete Journey

For any fast-growing system, one of the major problems it needs to solve is scaling. The system must be capable of handling lots of concurrent users. A crash is not an option. That can lead to major…

System Design
Databases

System DesignFeb 20264 min

System Design: Thundering Herd Problem in Distributed Systems

What is Thundering Herd Problem ? When CBSE 12th board result website announces that results will be out exactly at 10 AM on particular day. Before 10 AM, thousands of students are waiting and…

System Design
thundering-herd

Security & AuthDec 20254 min

How a Leaky Abstraction Led to an RCE in React Server Components

When RSC (React Server Components) were introduced, they significantly changed the landscape of React and modern web engineering. Writing backend or server-side code became much easier, and this approach appeared to solve long-standing SSR problems. ...

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AI & LLMsAug 20253 min

What is Agentic AI? A Beginner's Guide

A plain LLM cannot know anything that happened after it was trained. An agent is what you build when the answer has to come from the world rather than from the weights.

agentic-ai
ai

Web & JavaScriptMay 20254 min

TanStack Query: Deep Dive into Modern Server State Management

Server state is not client state, and treating it as though it were is where most data fetching code goes wrong. A look at what TanStack Query is actually doing underneath.

tanstack
state-management

Web & JavaScriptFeb 20255 min

Mastering the DOM: A Hands-On Guide with Examples

In this article, I will share my learnings from completing DOM challenges. This will help you understand how the DOM works and introduce you to commonly used methods and event listeners for DOM manipulation. Let’s get started! What is DOM ? The DOM (...

ChaiCode
HTML

Web & JavaScriptFeb 20253 min

Building JavaScript Polyfills Yourself

In this article we will understand what is the exact meaning of polyfill and also will cover how to approach the polyfill question in interview and will implement the code with dry run . Let dive into it ! 🚀 Why Polyfill ? Suppose you are developing...

ChaiCode
polyfills

Web & JavaScriptFeb 20253 min

JavaScript Array Lessons from Life😊

In this article, we are going to learn 10 JS methods that we can relate to our life experiences. so lets dive into it…. push() Method In life, to be successful, you need to push certain values into your ‘life’ array (your box), like discipline, cons...

JavaScript
chai-code

Computer NetworksJan 20253 min

Guide On HTTP Status Codes

Whenever the client (browser) sends a REST (GET, POST…) request to the server, the server responds back, generally with a JSON response that includes some kind of status code. We will learn about these status codes, but they reflect the state of the ...

ChaiCode
http

Computer NetworksJan 20254 min

How does TCP 3-Way Handshake work ?

Whenever there is some exchange of information between two hardware/software one thing that everyone is aiming for is reliability means that the data has sent successfully without any loss of piece of data in between irrespective of time the main foc...

TCP
tcp/ip-model

Computer NetworksJan 20255 min

Quick Guide: Understanding the OSI Model and Network Protocols

The OSI Model helps standardize the way computer systems send information to each other. In this article, you will learn about the seven layers of the OSI Model, their purposes, and the network protocols used by the model to send and receive data acr...

OSI Model
network protocols

Computer NetworksJan 20254 min

Client-Side Vs Server-Side : A Complete Guide For Beginners.

Often when you heard terms like client and server it hard to distinguish what is the key difference between them because both are software or hardware components that communicate over a network to exchange information. But what's the key difference b...

ChaiCode
Client Server Architecture

Computer NetworksJan 20254 min

How DNS Hierarchy Works: Exploring Root to Resolution

Have you ever thought ? what happens when you enter a query in that search bar ,Most of us don’t! But behind the scenes, a whole lot happens in the blink of an eye—within just milliseconds. ⚡ From your request to the response, there’s are lots of pro...

dns
dns resolver

Computer NetworksJan 20255 min

Complete Guide on Working of Internet

Have you ever wondered what happens in the background when you send a WhatsApp message to your friend? 🤔📱How does it happen so easily that we don’t even notice the number of things happening in milliseconds during the transfer of data? 🌐⚡ If you’r...

internet
ChaiCode

Computer NetworksJan 20257 min

Understanding Internet Jargons

Demystify internet jargons like HTTP, TCP, cookies, and DNS with simple analogies and explanations to understand tech terms…

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AI & LLMsMay 20242 min

Boost Productivity 10x with GPT-4 O

Boost productivity with GPT-4 O: advanced AI, real-time chat, voice mode, vision capabilities, and developer-friendly…

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DatabasesMay 20243 min

MongoDB vs MySQL: Beginner's Guide

Beginner's guide comparing MongoDB and MySQL, highlighting their structures, features, use cases, and…

Read

Security & AuthMay 20242 min

Access Tokens and Refresh Tokens Explained

Explore the roles of access tokens and refresh tokens in backend development for secure and seamless user…

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